I worked on improving the walking speed and autonomous behaviour of OctoRoACH, an inexpensive and robust palm-sized eight legged robot developed by the Biomimetic Millisystems Lab, together with my capstone project members and advisors at UC Berkeley. Our results show that reinforcement learning algorithms is useful to improve the walking speed of existing search and rescue robots across different terrains and save more lives during disaster situations.

关键词：步行机；腿式机器人；自动调谐；增强学习算法；行走速度

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Multidimensional data models form the core of modern decision support software. Yet real multidimensional instances are often unavailable for testing and benchmarking, and existing data generators can only produce a limited class of such structures. In this paper, we present a new framework for scalable generation of test data from a rich class of multidimensional models. The framework provides a small,expressive language for specifying such models, and a novel solver for generating sample data from them.

关键词：多维数据模型；决策支持软件；测试数据

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Capacitorless dynamic random access memory (DRAM) is a promising solution to cellarea scalability and complex fabrication process issues for conventional DRAM.The thin body SOI transistor, which suppresses the short channel effect and also minimizes variability, is selected for the capacitorless DRAM cell structure. The impact of substrate doping concentration on capacitorless DRAM cell performance is studied and a novel selective well structure is proposed.

关键词：动态随机存取存储器（DRAM）；通信操作指令（SOI）；纳米

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This thesis presents the underlying probabilistic model, the parameter estimation, and the inference algorithm of NET-VISA, Network Processing Vertically Integrated Seismic Analysis. NET-VISA is an Open Universe Probability Model (OUPM) for seismic events, the transmission of seismic waves through the earth, and their detection (or misdetection) at stations, as well as a model for spurious detections. The probabilistic model allows for seamless integration of various disparate sources of information. Applied in the context of the International Monitoring System (IMS), a global sensor network developed for the Comprehensive Nuclear-Test-Ban Treaty (CTBT), NET-VISA achieves a reduction of around 60% in the number of missed events compared to the currently deployed system. It also nds events that are missed by the human analysts who post-process the IMS output.

关键词：概率模型；参数估计；地震综合分析；国际监测系统（IMS）；传感器；网络开发

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Function calls are a basic primitive by which applications invoke services from external entities. In this paper, we propose “network calls” (netcalls), a general primitive to invoke advanced traffic processing services – such as firewalling or caching – from the network. We design and implement the netcalls API and a backend architecture to support netcalls, allowing end host applications to interact with services not only in their own access network, but any network their traffic traverses. Demonstrating the utility of netcalls, we built three applications to invoke netcalls, along with corresponding network services: interdomain firewalling for DDoS defense, ‘opportunistic’ traffic compression, and intrusion detection for mobile phones.

关键词：函数调用；网络电话；流量压缩；应用程序；防御

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Energy efficiency of computing devices has become a dominant area of research interest in recent years. Most of this work is focused on architectural techniques to improve power and energy efficiency; only a few consider saving energy at the algorithmic level. We prove that a region of perfect strong scaling in energy exists for matrix multiplication (classical and Strassen) and the direct (O(n2)) n-body problem via the use of 5D algorithms: This means that we can increase the number of processors by a constant factor, with the runtime (both computation and communication) decreasing by the same factor, and the total energy used remaining constant.

关键词：能量效率；计算设备；时间模型；能量模型；机器模型；5D算法

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Equation-based modeling languages provide an effective means to simulate the physical part of a cyber-physical system. Such languages are complex domain-specific languages that enable model engineers, such as mechanical engineers, to declaratively model the dynamics of systems.We evaluate this approach by embedding a series of equation-based modeling languages in Modelyze and using them to develop models.

关键词：方程建模语言；网络物理系统；建模；仿真

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In this paper we evaluate the need for a reinforcement learning algorithm to optimize the gait of OctoRoACH, a hand-sized eight-legged robot. We then perform an evaluation of a likelihood-ratio gradient policy and compare it against our hand-tuned results. Finally, we suggest a different approach to reduce the policy search space that can make the problem more manageable.

关键词：腿式机器人；步行机；强化学习算法；搜索范围

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We have investigated a wet chemical process for nanoscale texturing of sulfur-doped silicon (Si) surfaces, which results in substantial suppression of the reflectivity in a broad spectral range, leading to black Si surfaces. The blackened surface was characterized optically and with Veeco micro- profiler. We fabricated metal semiconductor metal (MSM) test devices using the aforementioned black silicon and electrically characterized them for current- voltage (I-V), optical response, zero biased quantum efficiency (QE), and optical responsivity. We observe increased optical response and responsivity for the blackened silicon. One key observation we have made is the extension of the detectivity up to 1.2 m, which is beyond 1.1 m for a typical silicon detector. This observation was made under zero bias to the detector. We conclude that anneling and metal enhanced chemical etching (MECE) treatment prior to fabrication of the devices have enhanced the detectivity of the devices beyond the typical bandgap of 1.1 m of silicon.

关键词：电子信息；半导体；光电探测器；黑硅

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We perform characterization of the pulse shape and noise properties of quantum dot passively mode-locked lasers (PMLLs). We propose a novel method to determine the RF linewidth and timing jitter, applicable to high repetition rate PMLLs, through the dependence of modal linewidth on the mode number. Complex electric field measurements show asymmetric pulses with parabolic phase close to threshold, with the appearance of waveform instabilities at higher currents. We demonstrate that the waveform instabilities can be overcome through optical injection-locking to the continues wave (CW) master laser, leading to time-bandwidth product (TBP) improvement, spectral narrowing, and spectral tunability. We discuss the benefits of single- and dual-tone master sources and demonstrate that dual-tone optical injection can additionally improve the noise properties of the slave laser with RF linewidth reduction below instrument limits (1 kHz) and integrated timing jitter values below 300 fs. Dual-tone injection allowed slave laser repetition rate control over a 25 MHz range with reduction of all modal optical linewidths to the master source linewidth, demonstrating phase-locking of all slave modes and coherence improvement.

关键词：电子信息；半导体；激光器；光注入

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